Tips from an Orchid Collector

Growing orchids as house plants offer an exciting challenge, and some amateurs have been particularly successful with their new hobby. 

Naturally, there have been failures also, because many find it difficult to extract from a book on orchid culture the directions which best fit their own conditions.

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The reason is that there is no generally applicable procedure. 

Making Tropical Orchids Happy

In order to find out what it takes to make tropical orchid plants happy, we must observe them in their native homes in order to bring the details of their requirements into clear focus.

I had my first chance to do this, four years ago, when I was invited to Venezuela as a consultant. As an incentive to come, I was offered the opportunity to spend five weeks collecting plants in the famous National Forest of Rancho Grande.

I shall never forget my first impression of entering this vast and wonderful preserve of primeval jungle, with its overwhelming richness and diversity of vegetation. 

Plant Paradise

The road by which we approached the National Forest (as is common in Venezuela) is cut out of a steep mountainside that it follows with sharp curves in all its windings. 

Its sides, strangely enough, are not covered with common roadside weeds, but with all kinds of fascinating plants, which seem to find favorable conditions there.

There I saw Gloxinia pallidiflora, with its rather large, bell-shaped, blue flowers. Another gesneriad noted was Diastema quinquevulnerum, with attractively red-marbled leaves and small, flesh-pink flowers in graceful sprays. 

Plants Galore

The only orchid in these places was the terrestrial, purple-flowered Bletia tuberosa which, however, sometimes occurs in masses.

In moist spots, Browallia americana created a blue carpet. 

A multitude of ferns, including tree ferns, grew in profusion. Behind them at the edge of the forest was another world altogether.

The trees were interlaced with creepers, and aerial roots hung down like a curtain. 

The trunks of the trees were covered with climbing aroids, ferns and begonias. Their branches, high over my head, were Iaden with bromeliads, orchids, ferns and a whole botanical garden of other plants.

I could hardly wait for my first excursion into this plant paradise.

The Conditions in the Natural Forest

Traveling in the jungle was either up or down steep slopes or over slippery leaves and slimy tree trunks and roots. This was tiring. Besides, within five minutes after entering the forest, 

High Humidity

I was literally bathed in sweat because of the very high humidity. Yet, the temperature rarely rose above 80° F. However, at this wonderful sight forgot all fatigue. 

The high humidity was, of course, largely responsible for the richness of the flora. You cannot have one without the other.

Constant Fog

Every afternoon, between two and three o’clock, it rained as if timed by a clock, sometimes with considerable violence.

A cool fog usually descended first from the tops of the mountains, which were always covered by clouds. 

This occurrence could be observed particularly well from the glassed-in veranda of the biological station. The fog came drifting down from one side and, like a drawn curtain, shut out the vista of lake and mountains.

Nigght Temperature

An hour later, the sun was shining again. Around 7:30 in the evening it became dark with tropical suddenness.

Then, within the next two or three hours, the temperature dropped 15 to 20°, so the nights were pleasant.

All of these are satisfied with the temperature we usually maintain in our homes, provided — and this is important — that a reasonable degree of humidity is maintained. 

It is not necessary to create the atmosphere of a steam bath, and 50 to 60 percent humidity is sufficient.

This amount of humidity, by the way, is more healthful also for the occupants than our customary desert-dry air.

Daily Rain in the Afternoon

Remember also that the daily rain of the jungle occurring in the afternoon demands daily syringing indoors.

In addition, the daily rain is not merely water, but brings with it dust from the air and dissolved bird droppings from the upper branches of the trees. In fact, it represents a mild daily feeding.

City tap water in general has very low mineral content. The osinunda fiber in which orchids usually are potted likewise offers very little nourishment. 

Orchids cannot live on anything, any more than other plants can. A mild feeding using a dissolved and highly diluted complete fertilizer, once a week, is advisable.

Warm Water for Orchids

Tropical rain never is cold, which means that cold tap water must not be used either. All water applied to orchids should have a temperature of about 60° F.

Do not forget either that the temperature drops at night, very important also for all plants in the home. 

The thermostat, therefore, should be set to 60° F. or slightly lower at night. The difference that this practice will make in the health of all plants, not only orchids, has to be seen to be believed.

Importance of Humidity

Orchids like other plants require a fair amount of light coming from a window. The presence of the radiator is no obstacle, provided a metal tray is placed on the window sill. 

Fill the tray with pebbles and enough water to nearly cover the pebbles on which the flower pots rest. By placing the pots on inverted saucers, direct contact between the pot and water can be prevented. 

Evaporation Increases Humidity

The gradually evaporating water increases the humidity of the air surrounding the plants. The heat of the radiator should be deflected into the room and must not be allowed to rise close to the plants. Cold drafts from windows during the winter must also be excluded.

South American Orchids

All these details may seem irrelevant, but they serve to define the conditions under which large numbers of South American orchids live. The Cordillera Costanera of Northern Venezuela, in which Rancho Grande is located and where I collected, is only 5000’ to 6000’ feet high. 

It has nothing to do with the Andes from which it differs very significantly in geology, as well as botany. The Andes which begin in Western Venezuela and extend through Colombia, Ecuador, and Peru, rise very much higher. 

Andean Orchids

Some of the most coveted Andean orchids, including certain beautiful odontoglossums, the species of cochlioda, Oncidium macratahum, and other large-flowered species, occur at and above 9000 feet. Here too, are found some of the finest of the lycaste, the rare Maxillaria sanderiana, and many others.

Contrasts in Temperature

At these heights, the summer (our late fall and winter) may be very hot. During winter (our early summer) the temperature drops to near the freezing point, and snow falls. 

Consequently, these high Andean orchids are difficult to maintain even in the greenhouse and are impossible in the home. Those from lower mountain reaches are accustomed to less variable temperatures. 

Among this group, which I collected in Northern Venezuela, are;

  • Epidendrums 
  • Certain Oncidiums 
  • Brassia 
  • Stanhopea 
  • Trichopilia 
  • Rodriguezia 
  • Chondrorhyncha 
  • Catasetums 
  • Gongora 
  • Mormodes

Naturally, these are much easier for the amateur to succeed with. To this list I would add the following; 

  • Cattleya 
  • Laelia 
  • Zygopetalum 
  • Chysis 
  • Trichocentrum
  • Peristeria 
  • Anguloa 
  • Cycnoches 

Others do not occur in this part of Venezuela, though they live under similar conditions.
43816 by Henry Teuscher